Proceedings Volume 2010 (format .pdf) - SimpBTH

BIOTECHNOLOGIC STUDIES REGARDING THE METABOLICACTION OF SOME PHYTOHORMONES WITH INHIBITION EFFECTOVER THE PLANT DEVELOPMENT - REVIEWEVELINA GHERGHINA * , GABRIELA LUTA * ,FLORENTINA ISRAEL-ROMING * , DANIELA BALAN ** University of Agronomic Sciences and Veterinary Medicine, Faculty of BiotehnologyBucharest, Marasti 59, sector 1, RomaniaABSTRACTThe discovery of substances with regulatory action over growth – phytohormones are growthstimulators, inhibitors, retardants – provided an efficacious, sensitive instrument for specialists inguiding and controlling the plant growth and development processes.The fact that phytohormones increase the efficiency of using fertilizers leads to some specialistsclaiming the superiority of crops supervision through bioregulators, over against chemical fertilizersbecause they do not contribute to the pollution of the environment.Following the basic mechanism of synthesis-transportation-action, the purpose of this paper is toestablish the mechanisms through which phytohormones with inhibitor properties can operate on plantevolution processes.Keywords: bioregulators, growth promoters, growth inhibitors.1. INTRODUCTIONIn a future “ecologic agriculture” that consider all environmental factors,phytoregulators have a great importance.Besides external environment factors (water, nourishing substances,temperature, light) for plants to grow and develop they also need substances thatform in their structure/ body – phytohormones. They influence the process ofgrowth and morphogenesis and they adjust the physiological processes fromdifferent tissues and organs of the plant. They are synthesized in the chloroplast ofyoung cells and they cumulate especially in the steams and roots growth zones, inseeds, pollen, buds, young tissues and others. [3]By intensifying the cellular division and elongating the existent cellsphytohormones make plants grow. This mechanism that causes plants to growdepends on the nature of the phytohormone. Chemically speaking, phytohormonesare highly heterogenic substances, similar to vitamins and animal hormones. Theyare composed of cyclical rings (indolic, purinic, iononic, gibbanic and others), theycontain ethereal bindings and different functional groups. They are largely spread innature and they can be found in different tissues and organs in superior plants, indregs, fungus, algae and in numerous microorganisms, in free form as well asassociated with proteins. [2]38